1. Technical Field of the Invention
The present invention relates to a tray capable of setting a thin plate-shaped member which is represented by an optical disk. Moreover, the invention relates to a recording apparatus constituted to transport a tray capable of setting a thin plate-shaped member represented by an optical disk.
2. Description of the Related Art
An ink jet printer according to an example of a recording apparatus has such a structure that an ink droplet is directly discharged to a label surface of an optical disc to be a thin plate-shaped member which is represented by a compact disc or a DVD (Digital Versatile Disc), thereby carrying out recording. In such an ink jet printer, generally, the thin plate-shaped member such as the optical disc is set to a tray having a plate shape and is transported (a secondary scanning feed) through a transport path in the ink jet printer in a setting state to the tray, and recording is thus executed.
There has conventionally been proposed a method of detecting a central position of an optical disc (a reference position for printing) in order to carry out the printing over a label surface (printing region) of the optical disc with high precision in such a manner that a shift in a printing position is not caused. As an example, JP-A-2002-127530 has disclosed a method of providing an identification mark on a tray and disposing an optical sensor in a bottom part of a carriage to be reciprocally driven in a primary scanning direction, that is, an opposed portion to the tray to sense the identification mark by means of the sensor, thereby obtaining the central position of the optical disc.
In the method described in JP-A-2002-127530, however, the whole optical disc is sensed in the primary scanning direction by means of the optical sensor, and subsequently, the whole optical disc is sensed in the secondary scanning direction in the same manner. For this reason, an amount of a movement of the carriage and an amount of a secondary scanning feed of the tray in the acquirement of the central position are increased. Accordingly, a long time is required for the sensing.
Moreover, the tray is apt to generate a slip together with the transport roller in the secondary scanning feed. Accordingly, it is preferable that the amount of the secondary scanning feed of the tray in the sensing should be smaller in order to enhance precision in the detection of the central position. Furthermore, it is preferable that the amount of the movement of the carriage should also be smaller in order to enhance the precision in the detection.